Investigation of corrosion–wear synergistic attack on nanocrystalline Cu deposits

In this work, the synergistic effect of corrosion and wear on nanocrystalline and microcrystalline copper deposits produced by pulsed and direct current electrodeposition processes was investigated. Dynamic polarization tests, electrochemical scratch tests and electrochemical scratch tests were carried out in NaOH and H2SO4 solutions, respectively. The mechanical and electrochemical contributions to corrosive wear of the deposits were separated and correlated to their mechanical and electrochemical properties. The study demonstrated that the synergistic effect of corrosion and wear on material loss depended on the microstructure, the environmental corrosivity and the wearing load. Corrosion can be significantly enhanced by mechanical attack. The ratio of the wear-accelerated corrosion rate to the pure corrosion rate of nanocrystalline copper was higher than that of the microcrystalline one in NaOH but lower in H2SO4 at a high scratch load, but the situation was reversed at a lower load. In corrosive wear, the damage of passive film in combination with metal removal could lead to rapid material loss.